The invention relates to new and useful improvements in power amplifiers, and particularly to power amplifiers having self-diagnosing impedance fault determination.
Radio frequency (RF) transmission devices are subject to impedance failures which can cause a high voltage-standing wave ratio (VSWR). Impedance failures not only interrupt the desired communication activity but the rsulting high VSWR can also lead to damage to system components from high reflected RF voltages. Locating such faults can be a time-consuming and difficult process, especially in such cramped and intense environments as airborne communications systems. In such environments quickly locating and correcting system faults is not only a matter of convenience and cost, but it can also make the difference between the success and failure of a mission or flight.
In currently available RF devices in the higher ranges (e.g. 1 GHz), it is possible to determine from an increased VSWR that a system component failure has occurred, but it is not possible to easily determine which component has failed. Time domain reflectometers are known, but they are very expensive and too large for frequencies in the Gigahertz ranges. This means that each possible failed component must be checked or replaced. If it were possible to determine which component has failed, then only that component could be replaced, thereby saving a large amount of time and perhaps preserving a vitally important mission. In addition, costly and weighty external test equipment would not be needed.
It is therefore an object of the present invention to provide an RF device in which impedance failures are quicker and easier to detect than in currently available devices.
It is another object of the present invention to provide an RF device which can determine in which of several system components a impedance failure has occurred.
It is a further object of the present invention to provide a time domain reflectometer for use in the Gigahertz frequency range.
Still other objects will become apparent in the following summary and description of a preferred embodiment of the invention.